This document discusses connections between astrophysics, acousmatic music, and mathematics. It provides examples of how sound can be used to represent astrophysical data and concepts. This includes sonifying radio spectral cubes to hear the structure of spiral galaxies and recipes for transforming the sound of black holes based on Einstein's equations. The document also mentions working at the intersection of multiple disciplines and potential topics for discussion, such as the languages of structure, performance, and cosmology as an explanation for existence. Collaborators in related fields are listed for potential future work.

1. Astrophysics and
Acousmatic Music
The art of throwing
everything in the air
and wondering where it went

2. Music of the spheres
This music was thought of
not as an audible sound,
but simply as a mathematical concept

3. Music of the n-dimensional hypercube

4. Acousmatic: sound one hears without seeing its originating cause
(Pythagorean disciples listened to his lectures from behind a curtain, unable to see him)

5. Acousmatic: sound one hears without seeing its originating cause
(Pythagorean disciples listened to his lectures from behind a curtain, unable to see him)
...it's the art of mental representations
triggered by sound, Homont [1996]

6. Acousmatic: sound one hears without seeing its originating cause
(Pythagorean disciples listened to his lectures from behind a curtain, unable to see him)
...it's the art of mental representations
triggered by sound, Homont [1996]
the sound world is not a space into which we can enter;
it is a world we treat at a distance, Goehr [1999]

7. Jodrell Bank, UK

9. working in the middle of extremes
10-9 ... 109
heisenberg: “can nature truly be this absurd?”

10. Astrophysicists try to describe the Universe
the seen and the unseen
real and hypothetical
using the language of mathematics
transforming noise into data
and data into knowledge

11. working with ambiguity
cosmology is an application of geometry
that takes on board quantum-mechanical uncertainty
to describe a space in which we might exist

12. working with ambiguity
music is an application of physics
that takes on board an intangible aesthetic
to contextualise a space in which we might exist
and increasingly utilises the Scientific Method (repeatable experimentation)

13. mathematics is not a verbal language

14. data sonification is acousmatic

15. ngc4501

16. ngc4501

17. ngc4501
Take a Radio Spectral Cube and turn it into sound.
The cube is like an image, but instead of each pixel being a single "colour",
it is actually an RF spectrum. Selecting a pixel with the mouse takes that spectrum
and transforms the radio frequencies into an audible range,
it then creates a sound with that spectrum.
Similarly, the radio frequencies have been transformed into visible colours
so you can see them, blue for "higher frequency" and red for "lower frequency".
You can see and hear the structure of the spiral arms,
even the discord in the middle where both are super-imposed.

18. Recipes for transformation
Ingredients A:
1 expanding universe
1 sound of your choosing
Take the expanding universe (e.g. FRW) and add sound with non-zero velocity relative to the
observer. Convolve the frequency of the sound (time-dependent spectrum) with both the
special relativistic frequency shift (due to the non-zero velocity) and the cosmological
redshift (frequency as a function of time). The observer will hear “geo-music”.
Ingredients B::
1 black hole solution of Einstein's equations
1 sound of your choosing
Take the black hole solution(e.g. Schwarzschild) and add the sound with non-zero velocity
relative to the observer. Convolve the frequency of the sound (time-dependent spectrum)
with both the special relativistic (due to the non-zero velocity) and the gravitational redshift
(frequency as a function of spatial position). The observer will hear geo-music. This can
also give "gravitationally lensed" sound. Of special interest would be an observer listening
to the music and simultaneously plunging into the black hole.

19. topics for discussion
mashematics
– messing with the languages of structure
– moving beyond sonification|musicology
convergence of complex systems
– maths|art|physics|music|philosophy|beliefs
– relevance to performance
cosmology
– “a system of beliefs leading to an explanation of
the mystery of existence” (Sandage, 1987)

20. Collaborators:
Andrew Newsam (Astrophysics + Software)
Peter Clive (Astrophysics, Nanotechnology + Piano)
Andrew Conway (Astrophysics + Solar Physics)
Aidan Keane (Cosmology)
Ulya Gumeniuk (Artist) www.ulyanagumeniuk.com
Jaakko Mattila (Artist) www.jasu.maasyke.fi
http://www.dgen.net
Gavin Starks B.Sc. M.Mus.
gavin@dgen.net